Prior art casing machines have assembled advancing lines of containers directly in the loading zone by pushing groups of containers sidewise until enough rows of containers were assembled there for casing. Two prior patents have assembled containers advancing down a conveyor line by alternately pushing groups of containers to the right and to the left, to subordinate conveyor lines, where they advance a short distance and are then pushed back toward a central loading zone to be loaded into cases. Examples of such casing techniques are shown in Keith U.S. Pat. No. 2,520,727, and Birk U.S. Pat. No. 4,211,056. Keith's FIGS. 18 through 23 and Birk's FIGS. 13 through 15E clearly show the alternate lateral pushing of groups of containers to right and to left, and their subsequent return, pushed back toward a central loading zone.
A major disadvantage of such prior art case loaders is their limitation to the delivery rate of filled containers advancing toward the loading zone along a single conveyor line, or down two parallel conveyor lines if the container filling operation is conducted on parallel lines, as suggested at Column 3, Lines 59-62 of Birk U.S. Pat. No. 4,211,056, and this delivery rate is reduced by interruption of conveyor operation during every case loading operation.
The lateral pushers propelling the arriving filled containers from the parallel conveyor lines inward toward a central loading zone between them must necessarily each incorporate a gate panel blocking the advance of oncoming filled containers, during the time a group of containers is being pushed inwardly from the conveyor toward the loading zone. This requires that the case loading operation necessarily proceeds at a slower pace than the container filling operation. In Column 4, Line 33, the Birk Patent refers to "staging areas A and B" disposed laterally on opposite sides of the loading station I. However, an examination of Birk's FIG. 15A clearly shows that staging areas A and B coincide exactly with conveyors 24 and 25, and there are no separate staging areas between these infeed conveyors and the loading zone, represented by the two trap doors 30 supporting the filled containers until they are lowered into the underlying case. The seizing, gripping and lowering of the filled containers from the loading zone downward into the underlying case necessarily occupies a predetermined finite length of time, during which a single column of filled containers may advance down each infeed conveyor. Until the case loading operation is completed, however, the trap doors of these prior art loaders must remain open, and no sidewise assembly or staging of these delivered filled containers can be performed while they are open and the conveyors are blocked.
With the unique modular casers of the present invention, however, delivery of filled containers along both infeed conveyors may proceed virtually without interruption.
This nearly continuous operation of the casers of this invention results from the incorporation of an assembly ramp positioned beside the loading zone, interposed between the loading zone and the infeed conveyor. Preferably two parallel infeed conveyors are employed, flanking the loading zone, each forming with the assembly ramp a separate assembly zone connecting each conveyor to the loading zone. One or two rows of filled containers may be in the process of assembly on one of these assembly ramps while the assembled containers from the other assembly ramp and conveyor are delivered to the loading zone, seized, gripped and lowered into the underlying case. At the same time, a new group of filled containers can begin assembly in the previously cleared assembly zone while the loading operation is proceeding to completion.
In this manner, the normal progression of filled containers along both delivery conveyors is virtually uninterrupted, and the brief delay caused by lateral pushing of containers from a conveyor onto the assembly ramp or into the loading zone results in minimum periods of interruption of the overall advancing conveyor columns. The delay occasioned by the seizing, gripping and lowering of the assembled group of filled containers through trap doors or otherwise, from the loading zone into the case, does not significantly delay the normal advance of filled containers along the infeed delivery conveyors.
Accordingly, a principal object of the present invention is to provide rapid and virtually uninterrupted casing operations performed upon two advancing lines of filled containers, closely matching the rate of container case loading to the rate of container filling for maximum efficiency.
Another object of the invention is to provide container case loading methods and apparatus utilizing a pair of assembly ramps flanking the loading zone, respectively interposed between the loading zone and one of the filled container delivery conveyors.
A further object of the invention is to provide modular casing methods and apparatus for advancing filled containers delivered by conveyor lines which may be employed with a single line and may subsequently be expanded to accept two infeed conveyor lines by making only minor additions and adjustments to the original casing apparatus.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the apparatus embodying features of construction, combinations of elements and arrangements of parts which are adapted to effect such steps, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.